Electric switch



A. C. GAYNOR Sept. 1, 1931.

ELECTRIC SWITCH Filed Aug. 8, 1928 2 Sheets-Sheet l IN VEN TOR. Ar/ Lr6@ 0r A T RNEY "A. C. GAYNOR ELECTRIC SWITCH Sept l, 1931.

Filed Aug. a, 1928 z'sneets-sheet 2 INVENTOR. A///urC-'f 2.1/0

TORNEY Patented Sept. 1l, 1931 PATENT FFICE ARTHURl C.. GAYNOR, QFSTRATFORD, CONNECTICUT ELECTRIC SWITCH Application. led August 8, 1928.Serial No. 298,218.

This invention relates to improvements in electric switches, and hasparticular reference n s 1 to switch arms and niouiitings therefor 11iquick acting or snap switches. 5 Heretofore, in snap or quick actingswitches-such as, for instance, those used in house wiring-the switchwas made a permanent,

and inseparable part of the actuating mechanism, so that it waspractically impossible to change the switch over from one having acertain arrangement of the switch arm or arms from one having adifferent arrangement of the'latter. Hence, it was the custom to pro'-vide a number of different assemblies of the switch actuating mechanismand switch arms for these diilerent uses, so that in making up a switch,the assembly having the yarrangement of switch arms needed for theparticular kind ofswitch wanted was selected and assembled in thesupporting means.

Now, itis an object of this invention to provide means whereby theswitch arm or arms may be applied to or removed from the switchactuating mechanism readily by hand and without the use of tools. Thus,in assembling a switch, if only one switch arm is wanted, only one isapplied to the actuating mechanism, and a saving in material and laboris effected. Again, if in practice it is desired to change over a switchfrom one kind to another, this may be done readily by changing thearrangement of the switch arm or arms on the actuating mechanism or byadding another arm in case only one was originally provided and two arewanted.

Further, according to the present invention, it is convenient and easyto interchange one kind or" switch arm with another and diferentswitch'arm. For insta-nce, the present inven- 40 tion provides twospecifically diii'erent'kinds of switch arms, one kind being adapted tobe electrically connected to the actuating mechanism, while the other isadapted to e insulated therefrom, and so arranges these that they areinterchangeably mountable on the actuating mechanism.

A further advantageous feature oi' this prol vision by the presentinvention of `means whereby one switch arm may be readily removed andanother applied is that it enables a switch arm, which has beenworn-out, broken, burnt or otherwise made defective in ilse, to bereplaced by a new and perfect switch arm, a result which cannot beobtained in switches heretofore provided, without necesv sitating thesubstitution ot' a new actuatm mechanism, or an entirely new switch.

In the exempliiication of this invention, herein described andillustrated, the switch arm comprises a pair of juxtaposed blades havingaligned apertures of non-circular formation adapted to be freely slidonto a portion of the actuating mechanisms which is similarly formed, sothat the switch arm may move bodily laterally on the actuating member,as when being applied to or rcmoved from the latter, but will oscillatewith the actuating member from one position of rest to another. Thislateral bodily movement ofthe switch arm is unrestricted by theactuating incmbei but is held within limits `by portions of thesupliorting structure for the moving parts of the switch. Asillustrated, it is limited on the one hand by a supporting frame for theactuating mechanism and on the other hand by a cover meniber for theswitch.

According to the resent invention, thc switch arm is not on y mountedfor bodily lateral movement but also may swing later- 8c ally a limitedextent on the actuating member; and the juxtaposed blades, when such Iconstitute the switch arm, have lateral swaying movement on theactuating member independently of each other, so that they may 35 shiftto properly engage the stationary con-v tacts to compensate forunequalities of manufacture and so that the blades being yieldinglyurged toward the stationary contact may1 have firm rubbing engagementtliere- 9o wit This latter feature enables the blades to be made ofstiff or non-flexing material, and

`thus the blades may be given a greater crosssectional area `withoutundue `width, and e5 may be composed of material having greaterelectrical conductivity than has been. possible with previously,proposed constructions wherein the blades themselves were mmhxrcsilient for the purposes above referia-l to.

F or yieldingly urging the blades toward themselves.

With the non-flexible blades of thepresent invention, the danger of theheat resulting from arcing, annealing the spring which yieldingly holdsthe blades together is reduced to a minimum, for the spring is locatedadjacent the mounting of the blades and remote from the contact engagingends thereof. In the switch blades heretofore proposed, the heat L,fromarcing frequently became so excessive as to anneal the springy blade andmake it non-resilient, so that it would fail to properly engage thestationary contact. w l

The present invention further guards aga-inst loss of proper contactbetween the blades and the stationary contacts by so arranging thespring which holds the blades together in operative position that.,should it become heated, the pressure produced against the blades willincrease rather than decrease, as it would do were the spring soformed'that it would expand upon being heated. t

Other features and advantages will hereinafter appear.

In the accompanying drawings, which are exemplary of the presentinvention,

Figure 1 is a top plan view of a switch with the cap or casing removed,soas to show the switch arms and their supporting means and coperatingstationary contacts.

FiO. 2 is a longitudinal section taken on,

the lines 2 2- of tFig. 1, the cap bridge and face plate being shown innormal position on the switch.

Fig. 3 is a transverse section taken on the line 3-3 of Fig. 2.,.

Fig. 4 is a disassembled perspective view of parts of the swi ch armshown `on the left-hand side of Fig. 3.

Fig. 5 is a disassembled perspective-view of the switch-arm shown on therighthand side of Fig. 3, and the switch arm actuating mechanism.

Fig. 6 is a diagrammatic view of the switch arm shown in Fig. 5, showingthe position to which the blades may move in dotted lines greatlyexaggerated for illus trative purposes.

Fig. 7 is a'modified form of spring device for holding thc blades of aswitch arm to gether.

Fig. 8 is an end View of a spring clip made in accordance with thisinvention. i

The switch shown in the accompanying drawings for the purpose ofillustrating the present invention comprises a base 10 having a cap orcover l1 (see Figs. 2 and 3) through which pass a pair of screws 12threaded in a metal strap or bridge 13 by means of which the base andeasing are held together in superposed relation. As shown, a flush plate14 is secured to the bridge 13 by screws 15. The casing 11, metal strap13 and iush plate 14 are provided with aligned openings through which ahande or finger-piece 16 extends for manual or other operation.

Supported by the base 10 and mounted within the base and casing 11 arestationary contacts 17, 18, 19 and 20, each of which has in electricalengagement therewith a binding screw 21 for connection to wires of oneor more electric circuits adapted to be controlled by the switch.

In most cases and as shown, the contacts 17, 18, 19 and 20 areelectrically insulated from each other. In a double pole double breakswitch, such as is shown, the contacts 18 and 20 are located at one sideof the base lOand adjacent the bottom thereof while the contacts 17 and19 are located at the other side of the base and extend upwardly asubstantial distance from the bottom of the hase, so as to bediammeti'ically opposite the contacts 18 and 20 respectively. The gapsbetween the two pairs of contacts 17-18 and 19-20 respectively, may bebridged or closed by switch arms 22 and 23 respectively, in one positionof rest of the switch andopened in the other position of rest.

The positions of'rest of the switch arms, that is the on and offpositions of the switch, vare controlled by the finger-piece orf handle16, which is made in accordance with my invention described andclaimedin niy copending application, Serial No. 276,886, f led May 11, 1928. Inthe switch shown, the handle 16 is provided with a rocker arni 211,

the portion 25 of which extends into a slot in the handle and isprovided with abearing opening aligning with bearing openings in thehandle to receive a bearing pin 26 which 'is also adapted to passthrough and be supported by side arms 27 of a frame 28 carried by thebase 10. The lower end of the rocker arm 24 engages a compression spring29 which is carried by a U-shaped crank 30. i The U-shaped crank 80 hasflat laterally extend,` ing arms 31 adapted to engage supportingfulcrums 32 provided on the frame 28. vIn the form shown, the fulcrums32 are of i-nverted tl-shape, but so far as the invention described andclaimed hereinjiS` concernei'hl they may be of any forni desired.TheaI-, rangement of the rocker arm 24 and the 4crank4 3() is such thatin position of rest the end of' the arm 211 is at one side of the axisof oscillation of the crank while the lower end of the crank 36 is atthe other side of said axis. Consequently, when the protruding side ofthe finger-piece 16 is depressed, the arm 24 is rocked and the spring 29is compressed storing sufficient energy so that after the arm 24 passesthrough the `axis of oscillation of the crank 30, the crank will besnapped quichly by the spring 29 vto the opposite side 3 1-, preferablyrectangular in cross section,

onto which the switch arms having rectangular apertures 22a and 23arespectively, may be slid. Thesizes and shapes of the extensions 32 ofthe apertures 22a and 23a respectively, are such that the switch armsmay be slid by hand onto the extensions 32 with `such freedom that theswitch arms may have lateral movement unrestricted by the extensions.Moreover, the extensions 32 are substantially identical in size andshape, as are the apertures 22a and 23a, so that either switch arms 22or 23 may be mounted on either extension, as desired.

Further, in 'accordance with the present invention, each switch arm isformed of a pair .of separate blades. These are designated 33 and 34 inthe switch arms 22 and 23 respectively, the blades of each pair beingshown separated in Figs. 5 and 4 respectively. These blades beingstructurally separate are capable of having lateral movement on theextensions each independently of its companion. For this purpose, in theblades 33 of the switch arm 22, which is ofthe kind usedwhen it is notnecessary to insulate t-he switch arm from the actuating mechanism,theapertures 22a are formed directly in the blade.

In the switch arm 23, however, which is of the kind adapted to beinsulated from the crank, each blade 34 is provided with a member 35 ofinsulating material in which the aperture" 23a is formed. Eachinsulating member 35 is provided with a flange 36 and a boss 37, theformerl being adapted to engage the outside face of a blade while theboss 37 extends through an aperture 38 in that blade and terminates inthe plane of the inner face of the blade. 37 are made non-circular sothat the insulating member 35 and the blade 34 together will oscillatewith the crank when the blade is mounted thereon. The insulating memberand its blade may be held together by any suitable means, it' beingsuflicient if the boss -37 merelyl slidingly fits the aperture 38 in theblade, -for other means provided by the lpresent invention and describedbelow will effectively hold the parts together in proper relation.

For convenience in handling the parts when assembling or re-arrangingthe switch, however, it is preferable that the boss 37 on the insulatingmember 35 and the aperture 38 in the blade have a press-fit, i. e. asnug tit The aperture 38 and the boss caused by forcibly pressing theboss into the aperture, so that the blade 34 and insulating member 35become after that a structural entity.

Notwithstanding the interpositioning of the insulating member 35 betweenthe blade 34 and the crank extension 32, the blades 34 may freely slideon the extension and may have the same other movements, characteristicsand advantages as the blades 33, the metal portions of which slidedirectly on the crank extension 32.

Irnthe disclosed embodiment of this invention, the pairs of blades 33and34 straddle their associated stationary contacts when they engage thelatter. Hence, each blade is provided with an off-setting bend 39between its central or mounting portion 40 and its contact ends 41. Theextent of this off-set is sufficient to allow the adjacent contact ends41 of each pair of blades to be spaced apart somewhat (slightly lessthan the thickness of the stationary contacts), whilethe centralportions 4() are in contact with each other face to face, as shown inFig. 3. This spacing of the contact ends 41 facilitates the entrance ofthe vstationary contacts between them and this the adjacent blades tospread and straddle the stationary contacts, and resiliently hold thecontact en`ds 41 'in firm' engagement with the stationary contacts. Thismeans, in the embodiment of the invention illustrated, consists of aspring clip 43, one being provided for each switch arm and each beingsubstantially U-shaped and having legs 44 adapted `to be slid over thecentral portions 40 of the juxtaposed blades constituting a switch armto straddle the same.

In the broader aspects of this invention, the spring clips 43 may beheld in place by any suitable means. For instance as shown in Fig. 7,the spring clip 43a may be permanently secured, as by rivets 45, toeither of the blades of a pair. However, to facilitate they manufactureand asembly of the device, to permit linterchange of one blade foranother without the use of tools, and foi` other reasons, it ispreferable that the spring clip 43 be structurally.y separate from theblades, as shown in Figs.A l to 5; and, to keep it in operative positionrelative to the blades, the legs 44 of the U-shaped spring clip 43 areprovided with apertures 46 conforming to the extensions 32 of the crank.

lIhus, when assembling the switch. the

pair of blades 33 or 34 (the latter with their by hand face to face withthe central portions 40 in contact and with` the apertures 22a and 23a,as the case lmay be, substantially aligned. Then the legs 44 of the U- 5shaped spring clip are spread and slid over the outside faces of thecentral portions 40 until the apertures 46 in the legs substantiallyalign with the apertures in the blades, the tension of the sprin clip 43being suicient to hold the parts rictionally together as a sub-assemblyat this time. And, finally, the assembly is slid onto the extension 32of the crank, the latter passing successively through the aperture 46 inthe inner leg 44 of the spring clip 43, then through the aperture 22a or23a-in the inner blade, then through the aperture 22a or 23a in theouter blade, and finally through the aperture 46'in the outer leg 44 ofthe spring clip. When thus mounted, the parts are held in alignment bythe extension 32 of, the crank and the spring clip presses them togetherwith the proper amount of tension. Yet, the switch arm assembly may movelaterally on the crank and the individual 'blades may move laterallyindependentl of each other both bodily and pivotally, or the apertures22a and 23a are made long enough to permit of slight skewing movement ofthe blades. Hence, the blades will locate and properly straddle thestationary contacts, even though there may be present slight variationsand inaccuracies resulting in the manufacture of the parts. Tocentralize or equalize the blades, the legs 44 of the U-shaped springclip 43 are made substantially wide andlie substantially flatagainst thecentral portions 40 ofthe blades which themselves are flat. Thus, thelegs 44 of the spring clip tend to hold all the parts fiat against eachother as shown in Fig. 6, and should a skewing or lateral swingingmovement of one or more of the blades occur when straddling a contact,the legs of the spring clip will return the parts to their normalpositions as soon as the switch is moved to off position.

The legs 44 of the spring clip for the blades 34 of the spring arm 23are insulated from the blades by the flanges 36 of the insulating member35 with which the legs directly engage, and the base 47of the springclip 43 is remote from the blades so as to be spaced therefrom by an airgap. Thus the blades 34 of the switch arm 23 are electrically insulatedfrom the crank, and yet, like the blades 33 of the switch arm 22, areheld together 4 by a spring clip.

Even if the insulating members 35 should.

or material of the blades but on the springclip 43. Therefore, theblades may be made, according to this invention, of the most suitablematerials (preferably an alloy of high copper content) and 4may have thedesired cross-section, reducing the internal resistance of the switch toa minimum. Moreover, v

since the material of the blades may be of high copper content, or purecopper for that matter, danger vof the blades becoming frozen to thestationary contacts by oxidizationduring periods of disuse is mitigated.

In practice, it has been found that-the arcs resulting from breaking ofcontact between the contact ends 41 of the blades and the stationarycontacts develop an intense heat which is, of course, conducted alongthe switch blade. vWhen the switch is operated vunder heavy load inrapid succession, it has been found that the heat developed tends toexpand the resilient means provided for holding the contact ends`against the stationary contacts, with the result that poor contact ishad, more arcing occurs', and more heat is developed.` To overcome thisdit'riculty, which is not so aggravated with a switch made in accordancewith this invention as with those heretofore proposed, VVthe spring clip43 of the present invention is so shaped that upon being heated thenormal space between the legs 44 decreases so that the pressure of thespring clip upon the blades increases when the switch heats up andcauses the blades to make tirm'er engagement with the stationarycontacts. To do this, the spring clip is provided between its base 47and the legs 44v with reverse bends 48 and 49, as shown in Fig. 8, on anenlarged scale. Thus, upon being heated, the portion of the clipsadjacent the bends 48 and 49 will tend to straighten out and assume thepositions shown in dotted lines in Fig. 8, with the result that the legstend to lie closer together and thus increase the pressure between them.

In order to keep the switch arm on the eX- tcnsions 32 so that it willnot slide thereoli' when the switch is in use, the extension 32 iscontinued outward so that its end lies so close to the portion 50 of theside wall of the casing l1 that no part of the device can slip betweenits end and the portion 50 of the wall. Operating lateral movement ofthe switch arni on the extension 32 of the crank held within the limitsby the wall 51 on the casing 11 and by walls 52 and 53 on the base l0.These walls 51, 52 and 53 form channels, one being provid'ed at eachside of the switch, in which the switch blades move,

the laterally bent ivings being adapted to engage these walls should theswitch arm move laterally too far either one way oranother. It should benoted that the upper portion of'the wall 53 cooperates with the wall tobe mounted upon-and removed from the extension 32 of the crank, and forother purposes, the frame 28 carrying the actuating mechanism isremovablymounted on the base. -In fact, it is just slidably mounted in'a socket arranged to lit it, but this feature also of the presentinvention is not claimed herein and forms vthe subjects-matter ofanother application. Suffice it to say that the actuating assembly shownin Fig. 5 is held in the hand while the switch arm sub-assemblycomprising the switch blades 33 and spring clip 34 is either slid uponor removed from the extension 32 after the frame 28 is replaced in the.base .and lateral movement of the switch arm is againheld within limitsby the base and casing. In this way, the switch arms 22 and 23 may bechanged around as kdesired by merey hand operations after the casing 11is removed, and any arrangement desired for a particular kind of switchmay be effected.

Variations and modifications may be made within the scope of thisinvention and portions of the improvements may be used with- Aoutothers.

HavingI thus described the inventiomwhat is claimed as new and for whichitis desired to obtain Letters-Patent, is

1. In an electric switch, a rocker; a crank;

a spring interposed between the rocker and crank and adapted to causethe latter to oscil- 'late with a snap action from one position of restto another when the spring is carried by the rocker across the axis ofoscillation of the crank; and a non-iexing, substantially rigid switcharm mounted on said crank for oscillation therewith and freely mountedon the crank for limited lateral swaying movement thereon.

2.` In an electric switch, a rocker; a crank: a spring interposedbetween the rocker and crank and adapted to' cause the lattter to4oscillate with a snap action from oneA position of rest -to anotherwhen the spring 1s comprising a pair of non-flexing, substantially rigidblades mounted in juxtaposed positions on said crank for oscillationtherewith and slidably mounted on the crankv for bodily lateral movementthereon independently of each other.

3.- In an electric switch, a rocker; a crank; a spring interposedbetween the rocker and crank and adapted to cause the latter tooscillate with a snap action from one position of rest to another whenthe spring is carried by the 'rocker across the axis of oscillation ofthe crank; and a switch arm comprising a pair of non-flexing,substantially rigid and separate blades mounted on said crank foroscillation therewith and freely mounted on the crank for limited andindependent lateral swaying movement on the crank.

4. In an electric switch, a base; a rocker; a crank; a spring interposedbetween the rocker and crank and adapted to cause the latter tooscillate with a. snap action from one position of rest to another whenthe spring is carried by the rocker across the axis of oscillation ofthe crank; a switch arm slidably mounted on the crank adapted tooscillate with the crank and at all times free from interference withthe crank to slide on and off the crank; and a removable closure devicefor the switch adapted to engage the base and having means which inoperative osition prevents removal of the switch arm rom the crank. v Y

5. In an electric switch, a rocker; a crank; a spring interposed betweenthe rocker and crank and adapted to cause the latterv to oscillate witha snap action from onev position of rest to another when the spring iscarried by the rocker across the axis of oscillation of the crank; aframe within which the crank is vmounted for oscillatory movements, saidlwhen the first-named switch arm'is carried by the iirst-namedextension; and a support in which the frame is removably mounted, saidsupport having means loc'ated in close I proximity to the end of eachextension to pre-c,

vent the switch armswhen carried thereby from sliding laterally. Saidextensions when said frameis in operative position on said support. l

6. A switch arm comprising a pair of struc- 4blades together, said cliphaving apertures aligning with the blade apertures so as to receive theoperating shaft and to be held in operative engagement with the `bladesby the operating shaft.

8. A switch arm comprising a pair of juxtaposed blades having aligningnon-.circular apertures adapted to receive a non-circular portion of anoperating shaft so as to rotate with the sha'ft; and a springclipstraddling the juxtaposed blades to yieldinglyhold the bladestogether, said spring clip having apertures conforming to thenon-circular portion yof the shaft and adapted to receivethe shaft andbe held in operative engagement with the blades by the operating shaft.

9. A switch arm comprising a pair of structurally separate juxtaposedblades having aligned apertures adapted to receive an operating shaft,portions of the blades containing said apertures being off-set inwardlyso that such portions mayengage while end portions of the blades arespaced to receive between them stationary contacts; and a spring clipfor yieldingly holding` in contact portions of the blades containing theapertures and also yeildingly holding the blades together so that thecontact engaging portions of the blades are equi-spaced at opposite endsof the switcharm. .y

10. A switch. arms comprising a pair of structurally separatejuxtaposed. blades having aligned apertures adapted to receive anoperating shaft, portions of the blades containing said apertures beingoE-set inwardly so that such portions may engage while theother'portions of the blades are spaced to receive between therestationary contacts, the

inwardly o1i-set portions being adapted to act as fulcrums for oneanother when it is necessaryl for the blades to spread a greater-distance at one end of the switch arm than at the other; and springmeans tending to hold the inwardy off-set portions flat against eachother to equalize the distance between the blades at their oppositeends.

11. A switch arm comprising a pair of structurally separate juxtaposedblades having aligned apertures through which an operating shaft mayextend; an insulating plate for each blade having a boss adapted to fitwithin the aperture in the blade,

said bosses having aligned apertures adapted to receive the operatingshaft, the bosses on the insulating plates terminating in the plane ofthe adjacent faces of the blades so that the blades may contact witheach other; and a spring clip adapted to hold together the blades withtheir insulating plates.l I U 12. A switch arm comprislng a pair ofstructurally separate juxtaposed blades having aligning aperturesthrough which an opbosses on the insulating plates terminatingin theplane ofthe adjacent faces of the blades so that the blades contact witheach other; and a spring clip adapted to yielding. ly hold together theblades with their insulating plates, said spring clip straddlingjuxtaosed blades and having apertures conforming to the non-circularportion of the shaft so that the spring clip is held in operativeposition relative to the blades and their insulating plates by theshaft, the insulatingl plates being interposed between the blades andthe spring clip so as to electrically insulate the blades from thespring clip and the shaft, and the straddling port-ion of the springclip being so far remotefrom the plates as to be out of electricalcontact with the blades.

13. A switch arm comprising a pair of identical, structurally separateblades having ofi-set bearing portions which when the blades are broughttogether causes the contact-engaging portions on adjacent blades to bespaced from each other, the bearin portion of each bladel being providedwith an insulating plate fitting within the off-set portion and having aboss fitting within an aperture in the blade, the boss on each plateterminating in the plane of the opposite face of 'the blad-e; and meansfor holding the blades together for operation.

14.151 switch arm comprising a pair of structurally separate juxtaposedblades, each` blade being provided with a molded insulating plate havinga boss extending into an aperture 'in the blade, said bosses beingprovided with aligned apertures adapted to receive a portion of a crankshaft.

15. A switch arm comprising a pair of structurally separate juxtaposedblades; and

resilient means for holding the vblades in' juxtaposed positions, saidmeans being so shaped that expansion thereof resulting from heatingcauses the tension of said means on the blade to increase.

16. In an 'electric switch; a rocker; a crank; a spring interposedbetween the rocker and crank and adapted to cause the latterv tooscillate with a snap action from one posi: tion of rest to another whenthe spring is carried across the axis of oscillation of the crank; apair of switch arms; and means on the crank for removably andinterchangeably supportinmsaid switch arms for oscillation therewith.

17. A snap switch comprising a support, a pair of contacts, an actuatingmechanism including an oscillatory element, an insulator having floatingconnection With said element, a Contact blade mounted upon saidinsulator, and means for restraining the lateral movement of said blade.

Signed at Bridgeport, in the county of Fairfield, and State ofConnecticut, this 7th day of August, 1928.

ARTHUR C. GAYNOR.

